Thermostatic circuit closer



WITNESS:

Aug. 24,1926. 1,597,630

C. A. SPENKS THERIIOSTATIC cmcun' CLOSER Filed July 25. 1924 INVENTOR ATTORNEY Patented Aug. 24, 1926.

UNITED STATES.

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' THEBHOSTATIC CIRCUIT CLOSER.

Application filed July 2s, 1924. Serial mhzzmw.

This invention relates to circuit closers, particularly those of the thermostatic-type, and has for its object the provision of a novel thermostatic circuit closer adapted for use in connection with signals, heating devices or in fact many other different kinds of apparatus whereby to close and open a circuit automatically depending upon the temperature. v

An important object is the provision of a device of this character which will be extremely simple andinexpensive in manufacture, easy to mount and set, efiicient in service, durable and a general improvement in the art.

With the above and other objects and advantages in view, the invention consists in the details of construction to be hereinafter more fully described and claimed, and illustrated in. the accompanying, draw ngs, in which Figure 1 is a plan view of one form of the device;

Figure 2 is a side elevation with a part broken away, and in section;

. gigure 3 is a plan view of a modified form, an Figure 4 is a side elevation thereof.

Referring more articularly to the drawings, and especial y Figures 1 and 2, the numeral 10 designates a base of suitable insulating material and of any desired size and shape depending upon the nature of the work to be done by the device. Mounted upon this base are two posts 11 which are naturally constructed of metal and which have'their heads formed with kerfs or slits 12 for a purpose to be described.

At its underside, the base 10 is formed with recesses 13 into which extend reduced threaded extensions 14 on the posts, and the base is formed with passages 15 leading into the recesses 13, within which passages are located terminal wires 16 carrying terminal In 17 of an eye-like nature engaged upon the threaded extensions 14 and held thereon by means of nuts 18. By this means it is quite apparent that the two posts form the terminals for the circuit closer device as a whole.

I also provide two elongated strips 19 of some metal having a high coefficient of expansion, which strips are bent into the spiral shape as shown and which are mounted upon the posts by having thelr inner .that I have thus ends engaged within the kerfs or slits 12. The

other ends of the strips 19, designated at 20, are free and constitute terminal arms upon the ends of which are secured contacts 21 riveted or otherwise fastened in place.

In the form of the invention illustrated in Figures 3 and 4, I provide a base 22 which is likewise constructed of some suitable in-.

sulating vmaterial and of any desired size and shape. However, in this form, the base is formed with a pair of spaced slots 23 having. mounted therein clips 23 within which are engaged the end ort'ions 24-0f elongated metallic strips 25 wiiich have their intermediate portions coiled into spiral shape as shown at 26 and which have their other ends free to define arms 27 on the terminals ofwhich are secured contacts 28.

The terminal connections in this case may consist of screws 29 which pass through laterally extended ends 30' of the clips and into the base, the wires 31 being suitably engaged by these screws."

In the operation of either form it will be apparent that under the influence of heat the metallic strips will expand and this will naturally result in moving the free ends of the strips outwardly so as to break the engagement of the contacts carried thereby. Reversely, the strips upon contracting under the influence of a reduced temperature, will bring the contacts into engagement for closing whatever circuit the device is used in connection with.

From the foregoing description and a study of the drawings, it will be apparent rovided an extremely simple and inexpensive thermostatic circuit closer which is capable of use for a wide. variety of purposes and in many arts, there the scope of the subjoined claim.

Having thus described the invention, I claim Y a In ,a device of the character described, a base of insulating material formed with a pairof slots, metallic clips located within one side of the base, said helical convolutions said slots, a pair of thermostatic metal strips engaging against the opposite side of the engaged Within said clips and having their base for yieldably holding the thermostatic intermediate portions coiled into a plurality strips in position, and terminal 'members of helical convolutions, contacts on one end carried by said laterally directed lugs. of said strips, laterally directed lugs on the In testimony whereof I afiix m si ature. other end of said strips engaging against CHARLES A. PE KS. 

